Ok here is the thing, there are two lines of reality and let me explain the two lines of reality:
1. First one is the one that you mentioned, in this reality, you are right, good looking guy that cant socialize for shit, he is awkward as hell for one reason or another. In fact, Elliot Rodger was not a bad looking dude. Not hell of hot but decent looking guy. While there are some dudes who are like George Costanza but they do get the girl, they do so by being great speakers, they don't speak with filler words such as " ummmm" "you know" "ah well" or "fauuuking yeah, fukking then this guy..." instead when these people speak, they have a strong voice and are well spoken and articulate and understand female emotions.
2. The second line of reality is what I have seen, it seems that they are moments in life that the good looking awkward guy with his social awkwardness and creepiness still gets the girl. Example is, I had two friends in the same situation, both were socially awkward, and lived with their parents. The good looking guy got a response from women such as:
"awww he is so shy but that's like sooo cute!!! and he live with his parents, I bet he loves his parents a great deal, total catch"
Ugly guy got this response:
" OMG what a fucking creep, dude doesn't talk, I bet he loves to chain women in his basement and OMG he also lives with his parents, like seriously is he going move out like ever!!??"
So yes, in some situations the good looking awkward guy can fail to get checks because of the lack of social skills and in some situation, he can be the biggest weirdo creep but still pulls it off under the guise of being "eccentric"